Jointed artificial hand



P. A INGOLD.

JOINTED ARTIFICIAL HAND.

APPLICATION FILED AUG. I, 1921.

Patentefi July 11, 11922 JOIN'IED ARTIFICIAL HAND.

LARZJZIPL Specification of Letters Patent.

Patented July 11, 31922.

Application filed August 1, 1921. Serial ItTo. 489,023.

To. aZZ whom it may concern:

Be it known that 1, PAUL ALFRED INGOLD, a citizen of the Republic of Switzerland, residing at 110 Rue dAngoulme, Paris, France, have invented new and useful Improvements in Jointed Artificial Hands, of which the following is a specification.

The present invention relates to an artificial hand which differs from those hitherto devised in that the fingers grasp an object and holdit with great firmness. According to the invention the first phalanges of the fingers are formed as extensions of the body portion of the hand and are integral therewith, while the second phalanges are pivotally jointed to the first phalanges.

Furthermore, this jointed hand comprises a locking device which so to speak locks, the parts in the closing position of the fingers, so that no effort needs to be exerted by the mutilated person, when once the parts are mechanically locked, in order to hold them so locked and thus keep the hand closed.

Moreover, the hereindescribed arrangement of jointed hand is such as to enable the thumb to co-act with the fingers of the hand in order to grasp an object.

Finally, the said hand is characterized by mechanical contrivances which, in addition to their being simple and strong, enable the mutilated person to easily move the hand.

The accompanying drawing illustrates a jointed artificial hand constructed in accordance with the invention.

Figure 1 illustrates the hand in a normal position, that is to say with the fingers closed. I

Figure 2 shows the hand open.

Figure 3 shows the hand about to grasp an object.

The hand as well as the fingers are made of the usual material. The body a of the hand, instead of stopping short at the joint of the phalanges and of being articulated to the latter, as has been hitherto practised, is not provided with such joints, but is formed integral with the rigid extensions Z), 7), 6 b which here take the place of the phalanges. At the end of these extensions are articulated the second phalanges c, c, 0 0 the same being integral with the third phalanges.

The thumb, articulated at a on the body a of the hand, is made of two parts (Z, (Z articulated at (Z and subjected to the action of a spring d which, exerting a pulling strain, tends to cause these parts to assume the normal position shown in Figures 1 and 2. V

Within the body a of the hand is arranged the mechanism as a whole. This mechanism comprises a base plate 6 suitably fastened to the said body and carrying a shaft 7, held in bearings f, 7. The said shaft is provided with a first set of four arms 7, 7", f and 7? connected to links 9, g, g and g jointed at g to the second phalanges c, 0, 0 and 0 It is furthermore provided with an external arm g connected to a link g ointed at a point of the thumb (Z, (Z. Finally, it is also provided with two other arms h, it, the one it of which is connected by a wire k to a spring 7&3 fastened at it to the body a of the hand and exerting a pulling strain, whilst the other It is connected to a string 2'. The said string passes around a roller 2" fastened to the body a and also around a roller 2' mounted on the heel of a toothed sector j pivoted on a stud y" and subjectedto the constant pull of a return spring j fastened to the plate 6. The sector j engages a pinion 7c mounted on an axis 70' carried in bearings fastened to the said plate 6. A projection or cam Z, integral with the pinion 7:, is adapted to engage a nose Z fastened to the arm it.

The operation is as follows: If, assuming the hand to be in a normal position, that is to say closed, as shown in Figure 1, it be desired to open the same, a pull is exerted on the string 2', thus causing the parts to pass from the position shown in Figural into that shown in Figure 2, in which latter the toothed sector 3' has moved, carrying with it the pinion 7c and projection Z; the latter, having separated from the nose Z, has enabled the arm h to tilt, carrying along with it the shaft f. In turn, the

latter, carrying along with it on the one hand the arms f 7, f and f, displaces the links 9, g, g and 9 which cause the second phalanges 0, '0, c and 0 to pivot around their axis Z7 whilst on the other hand it carries along the arm 9", which, through the intermediary of the link 9 acts upon the thumb d, (l, the latter being also pivoted. The parts then assume the position shown in Figure 2 and the hand has been opened.

it is sufiicient to release the string 2" in order that, as the parts again assume the position shown in Figure 1, under the action of the springs h and j the hand may grasp the object the mutilated person wants to take hold of. It may here be observed that, as soon as the projection Z re-engages its nose Z, the parts are locked in this position, without the necessity of any operation on the part of the person, in order to keep the hand in this closed. position.

On reference to .Figure 3, it will be seen what part may be played by the two-piece thumb, whenfor instance the object which the mutilated person wishes to grasp is placed upon a table. By pressing the thumb upon the table, the part d pivots relatively to the part (Z, thus allowing the second phalanx c to assume, relatively to the part 03, a lower position than in the case of Figure 1, which position is shown in Figure 3. It will therefore be readily seen that, on the second phalanx 0 closing down, it causes the said object to ride up onto the thumb.

It is desirable to remark that by transferring the operating action of the fingers to the second phalanges, contrarily to known systems wherein the phalanx itself is acted on, it is possible with a spring of equal strength in both cases, to secure a better grasp in the first case.

I claim: 1. An artificial hand comprising a body portion, finger members having their first phalanges integral with said body portion and second phalanges pivoted to said first phalanges.

2. An artificial hand comprising a body portion, finger members having their first phalanges integral with said body portion, second phalanges pivoted to said first phalanges and means for normally holding saidsecond phalanges in the closed position of the hand.

3. An artificial hand comprising a body portion, finger members having their first phalanges integral with said body portion, second phalanges pivoted to said first phalanges, means for normally holding said second phalanges in the closed position of the hand and means operable by the wearer for opening said second phalanges.

v4c. An artificial hand comprising a body portion, finger members having their first phalanges integral with said body portion, second ohalanges pivoted to said body portion and a thumb member fixed to said body portion.

An artificial hand comprising a body portion, finger members having their first phalanges integral with said body ortion, second phalanges pivoted to said first phalanges and a two-part thumb-member having one part pivoted to the body portion.

6. Angartificial hand comprising a body portion, finger members having their first phalanges integral withisaid body portion,

second phalanges pivoted to said first phalanges, a thumb-member consisting of two parts pivotally connected together, a tension spring between said parts below the point of connection, one of said parts being pivoted to the body portion. v

7. An artificial hand comprising a bodyportion, finger members integral with said body portion, second phalanges pivoted to said fin 'er members, a shaft mounted in said bocy portion, arms mounted on said shaft, links connecting said .arms to said second phalanges, means for locking said shaft, means for unlocking said shaft and automatic means for rotating said shaft'to close the hand.

8. An artificial hand for comprising a body-portion, finger-members integral with said body-portion, second phalanges pivoted to said finger members, a thumb member pivoted to said body-portion, a shaft'mounted in said 'body portion, arms mounted on said shaft, links connecting said arms to said second phalanges and thumb member, a lever arm on said shaft, a tension spring attached to one end of said arm and to the body portion, and a cord attached to the other endof said lever-arm and adapted to be operated by the wearer for'the purpose set forth.

9. An artificial hand comprising a body portion, finger-members integral with said body portion, second phalanges pivoted to a wheel and ratchet mechanism adapted to release said cam-face when the cord is pulled.

PAUL ALFRED INGO'LD. 

